A bomb squad responded to a report of heavy smoke at Pittsburgh Airport on Thursday and found a suspicious satchel concealed in a men's bathroom.
An airport concourse nearest the bathroom was shut down at 7:30 am (1230 GMT) after smoke was seen coming from the restroom, according to JoAnn Jenny, a spokeswoman for the Allegheny County Airport Authority.
The bomb squad was called to the scene and found a charred satchel inside a plumbing access panel, Jenny said.
Fire marshals were investigating why the satchel was there and how it caught on fire.
The concourse was reopened to the public at 11 am (1600 GMT). While it was closed, flights for Delta, American and United Airlines were redirected to another concourse.